Automated fluxless soldering using inert gas

Abstract

An apparatus for performing fluxless soldering includes an enclosure having a gas inlet through which an inert gas is introduced to create an inert gas-rich environment. Components are placed in the enclosure via an access port which also functions as a vent for allowing purge gases to vent from the enclosure. In one embodiment, a heating stage is provided in the enclosure which provides sufficient heat to reflow solder provided between two or more components. The inert gas is constantly flowing, or purging the enclosure in order to displace oxygen that would initially be present in the system. The presence of inert gas exclusive of other materials provides an oxygen-free environment, i.e., the inert gases provide a “shield” or environment around the parts to be soldered to inhibit the formation of additional oxides during soldering. The apparatus may also include an optics holder for transmitting light from an external light source into the enclosure, to permit visual alignment of component parts.

We claim:  
     
       1. A method for performing fluxless soldering comprising: 
       supplying inert gas into an enclosure, to form an inert gas-rich environment within said enclosure;  
       placing a first component in an abutting relationship with a second component in said enclosure via an access port;  
       heating one of the first and second components to a temperature sufficient to reflow solder between said first and second components; and  
       allowing purge gases to exit from the enclosure through the access port.  
     
     
       2. The method of claim  1  further comprising removing the soldered components from said enclosure through said access port. 
     
     
       3. The method as recited in claim  1  wherein supplying the inert gas includes providing an oxygen-free environment in said enclosure. 
     
     
       4. The method as recited in claim  1  wherein the method includes preventing oxide from forming on the solder during the heating process. 
     
     
       5. The method as recited in claim  1  wherein said enclosure is included in an automated assembly system. 
     
     
       6. The method as recited in claim  1  wherein said inert gas is selected from the group consisting of nitrogen, helium and argon. 
     
     
       7. The method as recited in claim  1  wherein heating one of the first and second components to a temperature sufficient to reflow solder between said first and second components comprises providing energy to a heating stage provided in said enclosure. 
     
     
       8. The method of claim  1  further comprising continuously supplying inert gas into the enclosure while accessing one of the first and second components via the access port.